Control, or switch handles are commonly used to control machinery such as construction and agricultural machinery. Such control handle includes a largely vertical shaft that can be grasped by a person""s hand, and a switch apparatus lying at the upper end of the shaft and having switches that can operated by at least one finger of the hand, such as the thumb. A hand rest is mounted at a bottom portion of the shaft to support the operator""s hand, as by supporting a side of the hand opposite the thumb.
Operators are most comfortable with the hand rest at a selected distance from the switch assembly, depending upon the size of the operator""s hand and the way in which he/she places his hand around the shaft. Control handles currently on the market are adjustable between three positions by pulling a pin out of one of three holes in a bottom part of the shaft, sliding the hand rest, and reinserting the pin. Such mechanism allows adjustment only between a limited number of spaced positions, and the operator""s hand may be comfortable only when the hand rest is between two of those positions. Also, adjustment requires manipulation from below the hand rest surface, which is often awkward especially when there is a wall close below the hand rest. The provision of holes also has the disadvantage of weakening the bottom part of the shaft. A hand rest for a control handle, which enabled rapid adjustment to any desire position within a given range, in a simple manner and with a minimum number of parts and with parts that cannot become lost, would be of value.
In accordance with one embodiment of the present invention, a control, or switch handle is provided for operating a machine, of a type which has a largely vertically elongated shaft, a switch apparatus at an upper end of the shaft, and a hand rest assembly at a lower portion of the shaft, wherein the hand rest assembly can be adjusted to a position suitable for almost any given worker, and can be adjusted without requiring operation in a confined area below the hand rest, and with a minimum number of separate custom parts. The hand rest assembly includes a clamp that clamps against the shaft to fix the position of the hand rest at substantially continuously variable positions along the shaft. Such clamping is accomplished by dividing the hand rest assembly into front and rear sections that are pivotally connected together. The rear section can be pivoted between a clamping position wherein it draws a location on the front section firmly against the shaft, and a release position wherein the second section allows the front section location to separate slightly from the shaft so the hand rest sections can slide along the shaft.
In one arrangement, the shaft is formed with a recess in each of its two laterally opposite sides, each recess forming a largely rearwardly-facing and primarily vertically-extending fixing edge. The rear section of the hand rest assembly forms a pair of clamping surface parts that each clamps against a corresponding one of the fixing edges as the rear section pivots from the release position to the clamp position. In the clamp position, the rear section forms a portion of the surface that can support a portion of the operator""s hand.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.